Air-compressor.



E. WlKl.

AIR COMPRESSOR, APPLICATION FILED 05c. 16, 1911.

1 1 99,5 1 5 Patented Sept. 26, 1916.

2 SHEETS-SHEET 1.

A TTORNE Y E. WIKI.

AIR COMPRESSOR.

APPLICATION FILED DEC. 16. 1911.

1 ,1 99,5 1 5 Patented Sept. 26, 1916.

2 SHEETS-SHEET 2.

//IIII IIIIIII/ IN VE N TOR WITNESSES Mbk/Q 5M $75 5y I if, 72 M dc gwEDWARD WIKI, 0F LUCERNE, SWITZERLAND.

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Application filed December 16, 1911.

To all whom it may concern:

Be it known that I, EDWARD WIKI, a citipressors and consists in novelprovisions made for the purpose of maintaining a substantially constantpressure in the reservoir passage or chamber into which the pumpdischarges without varying the speed of the compressor.

By the term air compressor used herein I mean to include reciprocatingor rotating compressors, pumps, blowers, or the like, adapted for movinga gaseous fluid.

The object of my invention is to provide simple and effective means ofthe kind and for the purpose specified adapted to control the pressureat the discharge end of the compressor by cutting off the admission tothecompressor ofthe fluid to be compressed whenever the deliverypressure rises above a predetermined value.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, and the advantages possessed by it, reference should be had tothe accompanying drawings and descriptive matter in which I haveillustrated and described a preferred form in which my invention may beembodied.

Of the drawings, Figure 1 is an elevation, partly in section, of aportion of a reciprocating air compressorprovided with my improvedpressure regulating means. Fig. 2 is a partial sectional plan taken onthe line 22 of Fig. 1. Fig. 3 is a sectional elevation taken on the line33 of Fig. 2. And Fig. 4 is a sectional elevation of a portion of theapparatus shown in Fig. 1, on a larger scale than Fig.1.

In the drawings, A, represents a reciprocating air compressor of commonform.

A represents the inlet passage through which the air to be compressedpasses to the compressing cylinder, and A represents the Specificationof Letters Patent.

bottom of the cylinder C Patented Se t. 26, 1916.

Serial No. 666,168.

connection through which the compressed airis discharged.

To the end of the passage A is secured a cylindrical valve casing C inwhich is mounted a rotary valve comprising a hub D and a cylindricalshell formed with ports D adapted to be moved into and out of registerwith the ports C formed in the wall of the casing U. The valve D issecured to a shaft D journaled in the valve casing U and with one endextending through the outer end of the casing. To the external end ofthe shaft D is securedan operating arm D The valve casing C is formedwith armlike extensions C and C The extension 0 isformed with a cylinderC A piston E working in the cylinder C has connected to it a piston rodE which is slidinglyreceived in the arm C or rather, as shown, in thehollow bolt F adjustably mounted in the arm 0*. The valve operating armD is connected to'the rod E between the arms C and C As shown, the arm Dpasses through an opening formed in an enlargement E of the rod E. Alight helical spring F surrounding the piston rod E, acts between thespring abutments F and F which engage the adjacent ends respectively ofthe piston rod enlargement E and the tubular member F This spring tendsto hold the valve D in the position shown in the drawings in which theports 0 andD are in register and the piston E engages the An arm Grsecured to the casing arm O forms a stop to limit the upward movement ofthe piston rod E to the amount required to move the ports D out ofregister with the ports C. It should be explained that the function ofthe light spring F is simply to insure the return of the'piston E andthe valve D to the position occupied by them in the drawings and it isnot the purpose of this spring to hold the piston E and the valve Dconnected to itin an intermediate position. In the form shown, where thepiston E is vertically movable and moves up to move the valve-member Dinto position to close the ports C, the spring supplements the action ofthe weight of the piston E and, if the latter is heavy enough, may beomitted.

To move the valve member D into position to close the ports C when thepressure at the delivery side of the chamber rises above a predeterminedvalue, a device responsive to the delivery pressure, is employed tocontrol the flow of a pressure fluid to the lower end of the cylinder CAs shown, this pressure responsive device comprises a member H providedwith a chamber H closed at its upper end by a flexible diaphragm I,secured to the member H by a washer H and bolts H As shown, the head ofone of these bolts is slotted at H? to receive one end of a lever Kpivotally connected to the bolt head by the pivoted pin K and the headof the diametrically opposed bolt H is slotted to receive and guide thelever and carries at its outer end an adjustable abutment screw Klimiting the rising movement of the lever. The diaphragm 1 hassecured toit a member J, the upper end of which is tapered and engages the seat Kformed for the purpose on the lever K. The lower end of the member Jextends'into the chamber H and is shaped to form a valve controlling theoutlet port H from the chamber. A pipe L connects the outlet passage Hto the lower end of the cylinder C and a pipe N connects the chamber Hto the outlet passage A of the compressor. A weight K adjustably securedon the arm K, with the latter, forms a loading device for holding themember J in position to close the port H except when the reservoir ordischarge pressure of the pump exceeds a predetermined value. When thispredetermined pressure value is exceeded the fluid pressure in chamber Hacting upwardly on the diaphragm 1 causes the valve J to open the port Hthus permitting air to pass from the chamber H to the lower end of thecylinder C whereupon the piston E at once moves upward the full amountof stroke permitted it and shifts the member D from the wide open.position to the fully closed position. The valve member D is held in itsclosed position until the diminution in pressure in chamber H permitsthe closure of the port H When this occurs the valveD is quicklyreturned to its wide open position by the weight of the piston E and theaction of the spring F. To permit this provisions are made for aconstant though restricted escape of air from the cylinder C and thepipe L. With the construction shown some leakage will take place out ofthe lower end of the cylinder C through the clearance space between thepiston E and the cylinder-wall and this is supplemented as shown by theleakage through the leakage passages H and may be supplemented also by arestricted discharge permitted through the valve 0 secured to the lowerend of the cylinder C The leakage through the leakage passages H may beregulated as desired through the needle valve M.

Those skilled in the art will understand that the mechanism shown formsa simple and eflective apparatus for regulating the operation of aircompressors operating at a fairly constant speed and which it is desiredto have maintain a substantially constant .delivery pressure.

The aggregate area of the ports C and of the ports D should be largeenough so that when the valve D is in the wide open position there willbe no wire drawing of the fluid to be compressed in passing through saidports. In practice, the aggregate crosssectional area of each of thesesets of ports is ordinarily at least as large as the crosssection of thepassage A. The valve D is entirely balanced so far as the action of thefluid passing through the ports D is concerned, and may be soconstructed that but little force is required to move it, especially aswhen it is in the closed position it need not absolutely seal the portC, since a r estricted leakage through these ports is without materialeflect upon the operation of the compressor. When the ports C are thusclosed the compressor delivers little or no compressed fluid and hencerequires ractically no power to operate it at its normal speed, as isdesirable.

One advantage ofthe pressure responsive device is that the lift of thevalve J may be very small say one-tenth or even one-twentieth of aninch.

While in accordance with the provisions of the statutes I haveillustrated and described the best form of my invention now known to me,it will be apparent to those skilled in the art that changes may be madein the form of the apparatus disclosed without departing from the spiritof my invention, and that under some conditions certain features of myinvention may be used with advantage without a corresponding use ofother features.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In combination with a pump of the kind described, a normally openbalanced valve controlling the inletpassage of said pump, and anoperating mechanism therefor, adapted to move said valve into its fullyclosed position when the delivery pressure rises above a predeterminedvalue, and to move the valve into its wide open position when thedelivery pressure falls to or below said predetermined value, said mechanism including a fluid. pressure supply conduit, a second valve, and afluid pressure de-, vice connected to said conduit through said secondvalve and adapted to move said balanced valve into its wide openposition whenever said second valve is opened, leakage provisionspermitting a restricted but constant escape of pressure fluid containedin said device to permit the closure of said balanced. valve when saidsecond valve is closed, and pressure responsive means for opening andclosing said second valve when the delivery pressure rises above andfalls to said predetermined value.

2. In combination with a pump of the kind described, a normally openrotary valve controlling the inlet passage of said pump and an operatingmechanism therefor, adapted to move said valve into its fully closedposition when the delivery pressure rises above a predetermined value,and to move said valve into its wide open position when the deliverypressure does not exceed said value, said mechanism including a chamberconnected to the delivery end of the pump, a second valve, afluidpressure actuating device for said rotary valve connected to saidchamber through said second valve and adapted to entirely close saidrotary valve when said second valve is open, leakage provisionspermitting a constant but restricted escape of fluid from said device,and means responsive to the pressure in said chamber for opening saidsecond valve when the delivery pressure rises above a predeterminedvalue, and for closing said second valve when the delivery pressure doesnot exceed said value.

3. In combination with a pump of the kind described a balanced valvecontrolling the inlet passage of said pump, a fluid pressure deviceadapted on the admission of a pressure fluid thereto to close saidvalve, and comprising a cylinder, a piston Working therein and connectedto said valve and means lightly tending to hold said piston and valve inthe wide open position of the latter, a chamber connected to thedelivery end of said pump and having an outlet connection leading tosald cylinder, and leakage provlslons permitting a restricted butconstant escape of the fluid under pressure contained in said cylinderand outlet connection, a second valve controlling said outletconnection, and operating provisions therefor responsive to the pressurein said chamber.

4. In combination with a pump of the kind described a rotary valvecontrolling the inlet passage of said pump, a cylinder, a piston workingtherein and connected to said valve, means lightly tending to hold thepiston and valve in the wide open position of the latter, a chamberconnected to the delivery end of said pump having a flexible diaphragmforming a portion of its wall and having an outlet connection leading tosaid cylinder, a valve secured to said diaphragm and controlling saidoutlet connection, an adjustable external loading device for thediaphragm, and leakage provisions permitting a restricted but constantescape of the fluid under pressure contained in said cylinder and outletconnection.

5. In combination with a pump of the kind described a valve controllingthe inlet passage of said pump and operating means therefor adapted toshift the valve between its wide open and its fully closed positions ona slight variation in one direction or the other of the deliverypressure from a desired maximum delivery pressure without maintainingthe valve in an intermediate throttling position, said means comprisinga pressure chamber and a pilot valve responsive to the delivery pressurecontrolling the pressure in said chamber.

EDWARD WIKI. Witnesses:

C. FIsHER, J ULIUs HARTMAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

